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django/tests/null_fk_ordering/tests.py

41 lines
1.9 KiB
Python

from django.test import TestCase
from .models import Article, Author, Comment, Forum, Post, SystemInfo
class NullFkOrderingTests(TestCase):
def test_ordering_across_null_fk(self):
"""
Regression test for #7512
ordering across nullable Foreign Keys shouldn't exclude results
"""
author_1 = Author.objects.create(name='Tom Jones')
author_2 = Author.objects.create(name='Bob Smith')
Article.objects.create(title='No author on this article')
Article.objects.create(author=author_1, title='This article written by Tom Jones')
Article.objects.create(author=author_2, title='This article written by Bob Smith')
# We can't compare results directly (since different databases sort NULLs to
# different ends of the ordering), but we can check that all results are
# returned.
self.assertEqual(len(list(Article.objects.all())), 3)
s = SystemInfo.objects.create(system_name='System Info')
f = Forum.objects.create(system_info=s, forum_name='First forum')
p = Post.objects.create(forum=f, title='First Post')
Comment.objects.create(post=p, comment_text='My first comment')
Comment.objects.create(comment_text='My second comment')
s2 = SystemInfo.objects.create(system_name='More System Info')
f2 = Forum.objects.create(system_info=s2, forum_name='Second forum')
p2 = Post.objects.create(forum=f2, title='Second Post')
Comment.objects.create(comment_text='Another first comment')
Comment.objects.create(post=p2, comment_text='Another second comment')
# We have to test this carefully. Some databases sort NULL values before
# everything else, some sort them afterwards. So we extract the ordered list
# and check the length. Before the fix, this list was too short (some values
# were omitted).
self.assertEqual(len(list(Comment.objects.all())), 4)